La influencia de la heterogeneidad ambiental en la diversidad morfológica y genética de Circaea lutetiana (Onagraceae) en los bosques hircanos

Environmental gradients are important factors that can potentially influence the genetic diversity and differentiation of populations. The present study examines the effect of environmental heterogeneity of the Hyrcanian forests on populations of Circaea lutetiana L. (Onagraceae). Using morphometrics, scanning electron microscopy (SEM) of leaf epidermis, and molecular markers, we analyzed genetic diversity and differentiation among nine populations from environmentally divergent habitats. Three different gene pools were observed. Our results indicate that the genetic structure is significantly correlated to environmental factors, but not to the geographical distance. Genetic clustering in C. lutetiana is affected by temperature, humidity, elevation, and average annual rainfall. Overall, our data indicate that gene flow does not contribute to explaining spatial patterns of genetic structure and the adaptation to the environment is the main factor shaping the genetic structure of the C. lutetiana populations. The populations belonging to each of the three gene pools have similarities in microclimate parameters, despite their geographical proximity, and populations from the same genetic pool can be up to 470 km apart. This evidence, as well as morphological and genetic similarities of the populations with greater geographical distance, suggest the possibility of cryptic speciation in this species.Los gradientes ambientales son factores importantes que pueden influir potencialmente en la diversidad genética y la diferenciación de las poblaciones. El presente estudio examina el efecto de la heterogeneidad ambiental de los bosques hircanos en las poblaciones de Circaea lutetiana L. (Onagraceae). Mediante un estudio morfométrico, microscopía electrónica de barrido (SEM) de la epidermis foliar y marcadores moleculares, analizamos la diversidad genética y la diferenciación entre nueve poblaciones de hábitats ambientalmente divergentes. Se observaron tres grupos genéticos diferentes. Nuestros resultados indicaron que la estructura genética se correlacionó significativamente con los factores ambientales, pero no con la distancia geográfica. La agrupación genética en C. lutetiana se vio afectada por la temperatura, la humedad, la elevación y la precipitación media anual. Nuestros datos indican que el flujo de genes no contribuye a explicar los patrones espaciales de la estructura genética y que la adaptación al medio ambiente es el factor principal que da forma a la estructura genética de las poblaciones de C. lutetiana. Las poblaciones que pertenecen a cada uno de los tres grupos genéticos tienen similitudes en términos de parámetros de microclima, a pesar de su proximidad geográfica, y poblaciones del mismo grupo genético pueden estar separadas hasta por 470 km. Esta evidencia, así como las similitudes morfológicas y genéticas de las poblaciones con mayor separación geográica, sugieren la posibilidad de especiación críptica en esta especie

Species delimitation and relationship in Crocus L. (Iridaceae)

The genus Crocus L. (Iridaceae) is monophyletic and contains about 100 species throughout the world. Crocus species have horticultural, medicinal and pharmacological importance. Saffron is the dried styles of C. sativus and is one of the world’s most expensive spices by weight. Controversy exits about the taxonomy of the genus and the species relationship. Exploring genetic diversity and inter-specific cross-ability are important tasks for conservation of wild taxa and for breeding of cultivated C. sativus. The present study was performed to study genetic variability and population structure in five Crocus L. species including Crocus almehensis Brickell & Mathew, C. caspius Fischer & Meyer, C. speciosus Marschall von Biberstein, C. haussknechtii Boissier, and C. sativus L. by inter simple sequence repeat (ISSR) molecular markers. We also used published internal transcribed spacer (ITS) sequences to study species relationship and compare the results with ISSR data. The results revealed a high degree of genetic variability both within and among the studied species. Neighbor joining (NJ) tree and network analysis revealed that ISSR markers are useful in Crocus species delimitation. Population fragmentation occurred in C. caspius and C. sativus. Both ISSR and sequenced based analyses separated C. sativus from the other studied species. Close genetic affinity of C. sativus and C. pallisii and inter-specific gene flow was supported by both data sets

Contemporary inter-specific hybridization between Cirsium aduncum and C. haussknechtii (Asteraceae): Evidence from molecular and morphological data

Cirsium aduncum Fisch. & C.A.Mey. Ex DC. and C. haussknechtii Boiss., (Asteraceae) are important medicinal plant species that grow in different geographical regions of Iran. We had no knowledge about population genetic structure, intra-specific and inter-specific gene flow and the presence of hybrid zone for this two species in Iran. Therefore, in order to provide data for conservation of these two medicinally important species, the population genetic analysis and morphometric studies were performed in 18 geographical populations of these species. ANOVA and MDS analyses revealed significant morphological difference among the studied populations in either species, while MDS plot showed morphological overlap in plants of these two species. AMOVA test revealed significant genetic difference among the studied populations. Mantel test showed positive significant correlation between genetic and geographical distances and the occurrence of isolation by distance. Population assignment test and STRUCTURE plot of genetic data revealed inter-specific introgression between these species

Cribado genético de cultivares diploides y tetraploides de algodón, basado en marcadores de polimorfismo de microsatélites en retrotransposones amplificados (REMAP)

Abstract Continuous artificial selection and cultivation of cultivars has led to genetic erosion and loss of useful genetic loci from the available germplasm. The objective was to evaluate diploid and tetraploid cottons cultivars with REMAP. Low genetic variability within each cultivar was observed, but a high genetic variability occurred within each species (18-68%). AMOVA test revealed 63% of total genetic variability occurred due to among species genetic difference. Unique alleles were detected in the studied species, that can be used for species discrimination. REMAPs could efficiently discriminate the studied diploid from tetraploid species and may be useful for fast screening, as genetic fingerprinting of large cotton germplasm and for planning future hybridization programs.Resumen: La selección artificial continuada y el uso de variedades ha llevado a erosión genética y pérdida de loci genéticos del germoplasma disponible. El objetivo fue evaluar variedades diploides y tetraploides de algodón por REMAP. Se observó baja variabilidad gené- tica dentro de cada variedad, pero alta dentro de cada especie (18- 68%). El AMOVA reveló que el 63% de la variabilidad genética total se produjo debido a diferencia entre especies. Se detectaron alelos únicos en las especies estudiadas, que pueden ser empleados para discriminación. REMAP podrían discriminar eficazmente las especies diploides de las tetraploides y ser últiles para el cribado rápido, actuar como huella genética del gran germoplasma de algodón y para la planificación de programas de hibridadción